The fun thing about 3800 it came it various dials, various metals, whereas, 5800 is a replica of 5711, slightly thicker than a 3800, with a curved outer case for 5800 vs the straight case for 3800.
5800 was produced within two years, patek decides to cut it off the production line, and concentrated on the larger size 5711. To me, they are both nice, but 5800 will have a far smaller production number than 3800. But i prefer 3800 for its more interesting variations